1. Field of the Invention
The present invention relates to an automated workpiece handling system for a machine tool and, more particularly, to a method and apparatus for transporting workpieces to, feeding workpieces onto, conveying workpieces along, feeding workpieces off of, and transporting workpieces from a machine tool.
2. Description of the Prior Art
Automated machinery is often used to perform a variety of operations on a workpiece, such as drilling and/or routing. A modern automated machine tool typically includes a plurality of workstations spaced along a movable worktable, with each of the workstations having an alignment device and a drilling and/or routing mechanism. The alignment device aligns and secures a workpiece, such as a group of printed circuit boards, to the worktable so that the drilling and/or routing operation can take place.
Previously, the workpieces have been inserted onto the alignment device of the individual workstations by hand. The machine tool then performs a programmed series of operations on the workpieces and the workpieces are manually removed upon completion of these operations. Thus, a typical automated machine tool requires the constant attention of a human operator.
The manual insertion and removal of workpieces from an automated machine tool is tedious work and can result in inefficient operation of the machine. Human labor is relatively expensive and should therefore be used for tasks which can best utilize the talents that a human operator has to offer. Furthermore, the manual handling of the workpieces can adversely affect the output efficiency of the machine because of the speed of the operator.
For some time, it has been recognized that a highly practical machine tool should have a fast, efficient system for bringing the workpieces to the workstations and for removing the workpieces after the operations are completed. It has been further recognized that such a system should operate in a relatively economical manner and should preferably not require any human labor. One attempt to provide an automated handling system for a machine tool is described and claimed in my copending application Ser. No. 236,844, filed Feb. 23, 1981, and entitled Handling System for an Automated Tooling Machine. Such handling system incorporates a transporter which carries the workpieces to the workstation of an automated tooling machine. The transporter incorporates a mechanism for feeding the workpieces onto the worktable at a selected workstation. The machine tool then incorporates a mechanism for carrying the workpieces from station to station.
The system of my copending application is relatively complex and since the loading mechanism is part of the transport means, the loading mechanism must be duplicated for each transport means and the transport means is complex and expensive. The conveyor belt system for moving the workpieces from station to station is also complex.